Reverse cantilevered tubular chair

ABSTRACT

A two-part, tubular chair having a cantilevered seat that is supported at the rear of the chair. The chair base frame is formed from two tubular members, one positioned within the other, which are bent together to provide sufficient structural strength to prevent deflection of the reverse cantilevered seat section A tubular back frame having a back rest member is removably secured to the base frame to complete the chair structure.

United States Patent lnventor Ralph K. Rye

102 Bellevue Road, Swampscott, Mass. 01907 Appl. No. 848,824

Filed Aug. 11, 1969 Patented July 20, 1971 REVERSE CANTILEVERED TUBULARCl-IAlR 8 Claims, 7 Drawing Figs.

US. Cl 297/445, 297/450 Int. Cl A47c 7/00, A47c 7/14 Field of Search297/239,

[56] References Cited UNITED STATES PATENTS 1,993,601 3/1935 Goldberg297/239 2,457,294 12/1948 Wood 297/447 2,519,096 8/1950 Addition a.297/447 Primary ExaminerCasmir A. Nunberg Attorney-Chittick, Pfund,Birch, Samu'els & Gauthier ABSTRACT: A two-part, tubular chair having acantilevered seat that is supported at the rear of the chair. The chairbase frame is formed from two tubular members, one positioned within theother, which are bent together to provide sufficient structural strengthto prevent deflection of the reverse cantilevered seat section A tubularback frame having a back rest member is removably secured to the baseframe to complete the chair structure.

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PATENTEB JUL20 I971 sum 2 OF 2 INVENTOR K p K- Rye m4 BM Luv 4 okra/dugREVERSE CANTILEVERED TUBULAR CHAIR BACKGROUND OF THE INVENTION Thisinvention relates to the design and manufacture of chairs in generaland, more particularly, to a reverse cantilevered, tubular chair inwhich the seat cantilevers forward from the rear legs of the chair.

In the manufacture of tubular chairs, it is important to provide a chairconstruction that maintains the structural relationships of the chaircomponents when the chair is subjected to the loading imposed by theweight of the occupant of the chair. If the tubular frame bends or givestoo much, the result ing change in structural relationships willseverely impair the designed comfort of the chair. The problem ofstructural deflection in a tubular chair construction is even morecritical in the case of chairs having a cantilevered seat.

It is accordingly, a general object of the present invention to providea cantilevered tubular chair construction having sufficient strength tomaintain its designed configuration under loading.

It is a specific object of the present invention to provide a two-part,reverse cantilevered tubular chair construction.

It is another object of the present invention to provide a reversecantilevered, tubular chair construction in which the chair base frameis formed from two tubular members, one positioned within the other,which are bent together to produce a continuous chair base frame.

It is still another object of the present invention to provide atwo-part, reverse cantilevered tubular chair construction that can beeasily fabricated and, thereafter, assembled without requiring specialtools, adhesives or other fastening devices to maintain the two chaircomponents in fixed relation.

These objects and other objects and features of the invention will bestbe understood from the following detailed description of a preferredembodiment, selected for purposes of illustration, and shown in theaccompanying drawings in which:

FIG. 1 is a view in front elevation of a reverse cantilevered chairconstructed in accordance with the present invention;

FIG. 2 is a view in side elevation of the chair;

FIG. 3 is a plan view ofthe chair;

FIG. 4 is a view in cross section taken along line M in FIG. 1 showingthe U-shaped configuration of the chair base frame;

FIG. 5 is a view in cross section taken along line in FIG. 3, with theseat and backrest members removed, showing the assembled relationship ofthe chair base frame and the chair back frame;

FIG. 6 is a view in cross section taken along line libb in FIG. 2showing the fastening of the base frame arm section to the back frame;and,

FIG. 7 is a front elevation of an alternative baclt frame construction.

Turning now to the drawings and particularly to FIGS. 1 through 5thereof, there is shown in varying views a two-part, tubular, reversecantilevered chair constructed in accordance with the, present inventionand indicated generally by the reference numeral 10. The reversecantilevered chair W has two major structural elements: a base frame anda back frame indicated generally by the reference numerals i2 and 14,respectively, in FIG. ll. These two frames, when assembled as shown inFIGS. 1 through 4, support a seat member 16 and backrest member 18.Specific details concerning the materials and assembly of the seat andbackrest members will be described below after first discussing theconstruction and configuration of the base frame 12 and the back frameM.

In the preferred embodiment of the invention, the chair base frame 12 isformed from two tubular members with one member positioned within theother. The two tubular members are then bent together as a unit toproduce a continuous structural element which defines the chair baseframe 12. Looking at FIG. 5, it can be seen that the base frame 12comprises two tubular members, an outer tubular member or tube 20 and aninner tubular member or tube 22 which extends beyond the end of theouter tube 20. A corresponding portion of the inner tube 22 alsoprojects beyond the end of the outer tube 20 at the left-hand side ofthe chair base frame 12 as viewed in FIG. 3. The extended portion 22a ofthe inner tube 22 mates with and frictionally engages the inner wall ofthe tubular back frame 14.

The two coaxial tubes 20 and 22 are bent together as a single unit toform the chair base frame 12. For purposes of identification, thecontinuous chair base frame 12 can be divided into the followingsections: a rearwardly opening, U- shaped support section 24 (FIG. 4)with vertically extending back legs sections 26 and 28 (FIGS. ll, 2 and5) which turn forwardly to form substantially horizontal arm sections 30and 32 (FIGS. 2, 3 and 5) which, at the forward ends, curve downwardlyand then backwardly to form substantially horizontal seat supportssections 34 and 36 (FIGS. 2 and 5) which terminate in the extended endportions 22a of the inner tube 22. The U-shaped support section 24 canalso be subdivided sectionally into two horizontal forwardly extendedleg sections 24a and 24b which are held in spaced, coplanar relation bythe transverse bar 240 of the U-shaped section.

It will be appreciated that the transverse bar 24c can per form itsfunction of maintaining the chair base frame legs 24a and 24b in spaced,coplanar relation in positions other than at the front of the chair. Forexample, if the chair base frame 12 is formed from two sets of coaxialtubes with each set having a forwardly extending leg section, avertically extending back leg section, a horizontal arm section and asubstantially horizontal seat support section, the transverse brace orbar 24c can be positioned at the back of the horizontal leg section sothat the Ushaped base support section 24 opens in a forward direction.Other configurations for the transverse bracing such as H" and X"members can be used if the chair base frame is formed from two sets ofthe coaxial tubular members. However, in the preferred embodiment of theinvention, the single, continuous coaxial tubular element is used toform the backwardly opening U-shaped support section and correspondingvertical leg sections, horizontal arm sections and seat sections.

The coaxial, double-tube construction of the chair base frame 12 isrequired for the reverse cantilevered chair of the present invention inorder to prevent undesirable deflection of the chair frame under theweight of the occupant. It has been found by experimentation that asingle-tube base frame having the same configuration as shown in FIGS. Ithrough 5 does not have sufficient strength to prevent the frame frombending forwardly. The deflection occurs in the single tube construction because the bending and pulling of the frame takes place in thestraight portions of the frame as well as in the curves, thus allowingthe seat to dip forwardly beyond the point of comfort for the occupant.Using a standard size single steel tubing, such as, a lowcarbon steeltube, either welded or seamless, having an outer diameter of 1 inch, thedeflection could not be overcome by employing a thicker walled tube.

The problem of frame deflection in the reverse cantilevered chairconstruction was solved by reinforcing the conventional steel tubingwith an inner steel tube of much lighter weight and smaller diameter. Areverse cantilevered chair base frame ll2 was constructed from standard,low-carbon steel tubing using an outer tube of 14 gage, l-inch outsidediameter and 22 gage inner tube having a 13/ l 6-inch outer diameter.The inner tube 22 was positioned within the outer tube 20 with a snugfit prior to bending. The two tubes, after being assembled in coaxialrelation to form a single continuous element, were then bent together asa unit into the configuration shown in FIGS. 1 through 5. As the twotubes were bent together, the inner steel tube 22 stretched therebytensioning the outer steel tube 20. Since the inner steel tube was bentinside of the outside steel tube, crushing and distortion at the bendson the exterior surface was reduced while the inside tube distorted andwrinkled to give added internal strength. The resulting doubletube baseframe 12 was stiff and had very little deflection and it provided morethan enough added strength to overcome the unwanted deflectionencountered with the single construction. However, it should beunderstood at this point that the type of material, the diameters andgages of the tubing used in the above example are by way of illustrationonly and should not be construed as limiting with respect to the reversecantilevered chair construction of the present invention.

The second major structural element of the reverse cantilevered chair,i.e., the back frame I4, is illustrated in FIGS. 1, 2, 3, and partiallyshown in FIGS. 5 and 6. In the preferred embodiment, the back frame I4comprises a single tube which is bent to form two downwardly andforwardly depending side sections 38 and 40 which are held in spaced andfixed relation by a transverse back section 42. Looking at FIG. 5, itcan be seen that the forwardly extending portions of the side sections38 and 40 slide over and are held in frictional engagement with theextended portions 220 of the chair base frame inner tube 22. The entireback frame, including the downwardly depending and forwardly extendingside sections 38 and 40, is located inwardly of the chair base frame armsections 30 and 32 and can best be seen in FIGS. 1, 2, 3 and 5. Althoughthis location is preferred, the side sections of the back frame can belocated on the outside of the chair base frame arm sections withoutdeparting from the scope of the invention.

The seat and backrest members 16 and 18, respectively, can be formedfrom any suitable material, such as, for example, fabric, leather orplastic. The use of a flexible material for the seat and backrestmembers is preferred because it allows these members to be slid over theseat support sections 34 and 36 and the back frames side sections 38 and40, respectively. However, it should be understood that the seat andbackrest members 16 and 18 can be formed from a relatively rigidmaterial, such as, wood, plastic or metal and then hung from orotherwise secured to the appropriate seat support and back frame sidesections.

Turning now to FIGS. 5 and 6, the preferred embodiment of the inventionutilizes a fastening means between the substantially horizontal annsections of the base frame and the downwardly depending side sections ofthe back frame. As shown in FIG. 6, the fastening means comprises a pin44 which is threadably secured to the ann section of the outer and innertubes 20 and 22. Each back frame side section has an aperture 46 toreceive the pin 44 in frictional engatement. A corresponding aperture 48is provided in both sides of the back rest member 18 at a point thatwill line up with the pin 44 and back frame aperture 46 when thebackrest member is positioned on the back frame as shown in FIGS. ll, 2and 3.

The pins 44 keep the material of the backrest member 18 in place and indoing so eliminate the chance of the back frame and arm rattling wherethey cross. The pins also serve to exactly position the two chair frameparts and, when weight is applied to the seat, the pins transfer thepressure to the back legs. The pressure transfer keeps the seat fromsagging and changing the comfort angles of the seat and back. Thisconstruction eliminates the chance that over a long period of use thebend at the front where the arm and seat support sections flow togetherwill not stretch out causing permanent changes in the angles of seatingfor comfort.

FIG. 7 illustrates an alternative construction in which the backrestmember 18 is secured to the back frame side sections 38 and 40 by meansof a plurality of braces as and corresponding suitable fasteners 52. Inthis configuration, the combination of the back rest and braces servesthe dual pur pose of holding the side sections 38 and 40 in the desiredposition and at the same time, provides a support for the chairoccupants back.

The combined back frame-backrest construction shown in FIG. 7 can alsobe employed in another embodiment of the invention. It has already beenmentioned that the chair base frame 12 can be formed from two'sets ofcoaxial tubes and a transverse brace to maintain the horizontal legsections in spaced, coplanar relation. Since the combined backframebackrcst construction shown in FIG. 7 performs the same function asthe back frame transverse bar 42, i.e., holds the side sections 38 and40 in spaced, fixed relation, it will be appreciated that if the baseframe is formed from two sets of coaxial tubes, the sets can be extendedin length enough to form the upstanding side sections 38 and 40 as acontinuous structural element. In this embodiment, the reversecantilevered chair I0 has a chair frame comprising two sets of coaxialtubes with each set having a forwardly extending leg section, avertically extending back leg section, a substantially horizontal armsection, a substantially horizontal seat support section and avertically extending side section. The two sets of bent coaxial tubesare held in spaced relation by suitable means, such as, the transversebrace 24c between the two forwardly extending leg sections and by meanspositioned between and secured to the two vertically extending sidesections 38 and 40, such as, the transverse bar 42 or the combined backframe-backrest construction shown in FIG. 7.

Having described in detail the preferred embodiment of my invention,what I claim and desire to secure by Letters Patent of the United Statesis:

I. A reverse cantilevered, tubular chair comprising:

a chair frame formed from two tubular elements, each tubular elementcomprising two tubular members, one posi tioned within the other, saidchair frame tubular elements each being bent into a forwardly extendinghorizontal leg section which turns upwardly at the rear to form avertically extending back leg section which turns forwardly at the upperend thereof to form a substantially horizontal arm section which, at theforward end thereof, curves downwardly and then backwardly to form asubstantially horizontal seat support section and finally turns upwardlyto form a substantially vertical side section;

means for maintaining said chair frame forwardly extending, horizontallegs sections in spaced, coplanar relation;

means for maintaining said upwardly extending, substantially verticalside sections in spaced, fixed relation; and,

a seat member mounted between said seat support sections 2. A reversecantilevered, tubular chair comprising:

a base frame formed from two tubular elements, each tubular elementcomprising two tubular members, one positioned within the other, withthe inner tubular member being longer than and extending beyond one endof the other tubular member, said base frame tubular elements each beingbent into a forwardly extending horizontal leg section which turnsupwardly at the rear to form a vertically extending back leg sectionwhich turns forwardly at the upper end thereof to form a substantiallyhorizontal arm section which, at the forward end thereof, curvesdownwardly and then backwardly to form a substantially horizontal seatsupport section which terminates in the extended portion of the innertubular member;

means for maintaining said base frame forwardly extending,

horizontal legs sections in spaced, coplanar relation;

a back frame comprising: two tubular side members fitted over theextended portions of said base frame inner tubular members, said sidemembers extending backwardly and upwardly, and means for maintaining theupwardly extending portions of said side members in fixed, spacedrelation; and,

a seat member mounted between and removably secured to said seat supportsections.

3. The chair of claim 2 further characterized by said means formaintaining the upwardly extending portions of said side members infixed, spaced relation including a backrest member.

4. A reverse cantilevered, tubular chair comprising:

a base frame formed from two tubular elements, each tubular elementcomprising two tubular members, one positioned within the other, withthe inner tubular member being longer than and extending beyond one endof the other tubular member, said base frame tubular elements each beingbent into a forwardly extending horizontal leg section which turnsupwardly at the rear to form a vertically extending back leg sectionwhich turns forwardly at the upper end thereof to form a substantiallyhorizontal arm section which, at the forward end thereof, curvesdownwardly and then backwardly to form a substantially horizontal armsection which, at the forward end thereof, curves downwardly and thenbackwardly to form a substantially horizontal seat support section whichterminates in the extended portion of the inner tubular member;

means for maintaining said base frame forwardly extending,

horizontal legs sections in spaced, coplanar relation;

a tubular back frame having a substantially horizontal transverse backsection and two downwardly and forwardly depending side sections, saidside sections being fitted over the extended portions of said base frameinner tubular members;

a seat member mounted between and removably secured to said seat supportsections; and,

a backrest member mounted between and removably secured to said backframe side sections.

5. The chair of claim 4 further characterized by means for fastening thedownwardly depending side sections of said back frame to arm sections.

6. A reverse cantilevered, tubular chair comprising: a base frame formedfrom two tubular members, one positioned within the other, with theinner tubular member being longer than and extending at each end beyondthe outer tubular member, said base frame having a rearwardly opening,U-shaped support section with vertically extending back leg sectionswhich turn forwardly to form substantially horizontal arm sectionswhich, at the for-,

ward ends thereof, curve downwardly and then backwardly to formsubstantially horizontal seat support sections which terminate in theextended portions of said inner tubular member;

a tubular back frame having a substantially horizontal transverse backsection and two downwardly and forwardly depending side sections, saidside sections being fitted over the extended portions of said base frameinner tubular member;

a seat member mounted between and removably secured to said seat supportsections; and,

a backrest member mounted between and removably secured to said backframe side sections.

7. The chair of claim 6 further characterized by means for fasteningsaid downwardly depending side sections of said back frame to said armsections.

8. The chair of claim 7 further characterized by said back frame sidesections being located inwardly from said base frame arm sections.

1. A reverse cantilevered, tubular chair comprising: a chair frameformed from two tubular elements, each tubular element comprising twotubular members, one positioned within the other, said chair frametubular elements each being bent into a forwardly extending horizontalleg section which turns upwardly at the rear to form a verticallyextending back leg section which turns forwardly at the upper endthereof to form a substantially horizontal arm section which, at theforward end thereof, curves downwardly and then backwardly to form asubstantially horizontal seat support section and finally turns upwardlyto form a substantially vertical side section; means for maintainingsaid chair frame forwardly extending, horizontal legs sections inspaced, coplanar relation; means for maintaining said upwardlyextending, substantially vertical side sections in spaced, fixedrelation; and, a seat member mounted between said seat support sections2. A reverse cantilevered, tubular chair comprising: a base frame formedfrom two tubular elements, each tubular element comprising two tubularmembers, one positioned within the other, with the inner tubular memberbeing longeR than and extending beyond one end of the other tubularmember, said base frame tubular elements each being bent into aforwardly extending horizontal leg section which turns upwardly at therear to form a vertically extending back leg section which turnsforwardly at the upper end thereof to form a substantially horizontalarm section which, at the forward end thereof, curves downwardly andthen backwardly to form a substantially horizontal seat support sectionwhich terminates in the extended portion of the inner tubular member;means for maintaining said base frame forwardly extending, horizontallegs sections in spaced, coplanar relation; a back frame comprising: twotubular side members fitted over the extended portions of said baseframe inner tubular members, said side members extending backwardly andupwardly, and means for maintaining the upwardly extending portions ofsaid side members in fixed, spaced relation; and, a seat member mountedbetween and removably secured to said seat support sections.
 3. Thechair of claim 2 further characterized by said means for maintaining theupwardly extending portions of said side members in fixed, spacedrelation including a backrest member.
 4. A reverse cantilevered, tubularchair comprising: a base frame formed from two tubular elements, eachtubular element comprising two tubular members, one positioned withinthe other, with the inner tubular member being longer than and extendingbeyond one end of the other tubular member, said base frame tubularelements each being bent into a forwardly extending horizontal legsection which turns upwardly at the rear to form a vertically extendingback leg section which turns forwardly at the upper end thereof to forma substantially horizontal arm section which, at the forward endthereof, curves downwardly and then backwardly to form a substantiallyhorizontal arm section which, at the forward end thereof, curvesdownwardly and then backwardly to form a substantially horizontal seatsupport section which terminates in the extended portion of the innertubular member; means for maintaining said base frame forwardlyextending, horizontal legs sections in spaced, coplanar relation; atubular back frame having a substantially horizontal transverse backsection and two downwardly and forwardly depending side sections, saidside sections being fitted over the extended portions of said base frameinner tubular members; a seat member mounted between and removablysecured to said seat support sections; and, a backrest member mountedbetween and removably secured to said back frame side sections.
 5. Thechair of claim 4 further characterized by means for fastening thedownwardly depending side sections of said back frame to arm sections.6. A reverse cantilevered, tubular chair comprising: a base frame formedfrom two tubular members, one positioned within the other, with theinner tubular member being longer than and extending at each end beyondthe outer tubular member, said base frame having a rearwardly opening,U-shaped support section with vertically extending back leg sectionswhich turn forwardly to form substantially horizontal arm sectionswhich, at the forward ends thereof, curve downwardly and then backwardlyto form substantially horizontal seat support sections which terminatein the extended portions of said inner tubular member; a tubular backframe having a substantially horizontal transverse back section and twodownwardly and forwardly depending side sections, said side sectionsbeing fitted over the extended portions of said base frame inner tubularmember; a seat member mounted between and removably secured to said seatsupport sections; and, a backrest member mounted between and removablysecured to said back frame side sections.
 7. The chair of claim 6further characterized by means for fastening said downwardly dependingside sections of said back frame to said arm sections.
 8. The chair ofcLaim 7 further characterized by said back frame side sections beinglocated inwardly from said base frame arm sections.